A casino, also called a gaming house or a gambling hall, is an establishment that offers various types of gambling. Most casinos offer a variety of card and table games, such as poker, blackjack, craps, roulette, and video slots. Often, they offer complimentary items to gamblers, known as comps. Casinos often have security measures in place to prevent cheating or collusion. Most states regulate casino gambling. The revenue from casinos can be very significant for the owners, investors, and Native American tribes. Local governments may impose taxes on casino revenues to help control the industry.

Although gambling probably existed in primitive form as early as recorded history, the casino as a gathering place for different forms of gambling did not develop until the 16th century, when a gambling craze swept Europe and Italian aristocrats opened private parties called ridotti. These were social events where gambling was the primary activity.

The modern casino is usually a large building that houses many tables and slot machines. It is often located in a tourist area and designed around noise, light, and excitement. The games offered are regulated by law and the staff is trained to detect cheating and other irregularities. Security measures include catwalks that allow surveillance personnel to look directly down, through one-way glass, on the tables and slot machines.

Some casinos specialize in specific games, such as blackjack or baccarat. Others feature a mixture of games. Many offer Asian games such as sic bo (which spread to several European and American casinos during the 1990s), fan-tan, and pai-gow.